<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="jquery-3.3.1.min.js"></script>
</head>
<body>
<img src="img/star.gif" alt="图片" style="width: 300px;border-radius: 30px;box-shadow: 8px 8px 5px #666;">

</body>
<script>
    $(function () {
        $('img').css('border-radius')//查询
        $('img').css('border-radius','50%')//设置
        $('img').css('boxShadow','10px 10px 5px #f55')
        $('img').css('box-shadow','10px 10px 5px #0f0')
        $("img").css({"border-radius":"20%","boxShadow":"10px 10px 5px #00f"})
        $("img").css("borderRadius",function (i,curval) {//加入回调函数
            return Math.round(1.8*parseInt(curval));
        })
    })
</script>
</html>